In recent decades, with the improvement in both the continuous casting technology and the online computer control degree, it has become a wish of metallurgical industry of countries in the world to lower the energy consumption and manufacturing cost of the steel industry. Therefore, casting molten steel directly into finished products has become a goal pursued by researchers.
One of the main manners of continuous thin strip casting is that the molten steel passes through a crystallization roller in high-speed revolution and solidifies into cast strips of 2-5 mm under the rolling force. The basic technological process of current continuous thin strip casting is: thin strip continuous casting device (twin-roller, single-roller and wheel-belt type)→closed chamber→loop→pinch roller→hot rolling (single-stand, twin-stand or none)→controlled cooling→coiling. Introducing the molten steel from a steel ladle through a long nozzle, a tundish and a submersed nozzle to a molten pool formed by rotating water-cooling crystallization rollers and side dams, then forms cast strips through cooling by water-cooling crystallization rollers. After that, delivering the cast strips to a cast strip conveying roller pass by the swinging guide plate and the pinch roller, and then reach a coiling machine by the hot rolling mill, spray cooling and flying shear.
By virtue of advantages like cost saving, plant area reduction, energy consumption reduction, production efficiency improvement, etc., the continuous thin strip casting technology has become a hot subject among researchers all over the world, and it is called a revolutionary technology of the metallurgical industry.
At present, continuous thin strip casting mainly ha two problems: (1) at the preliminary stage of pouring, the high-temperature molten steel tends to solidity when flowing from the tundish nozzle into a delivery device and from a small hole of the delivery device to a space between twin rollers; (2) in the process of pouring the molten steel for a long time, the molten steel flowing from the ladle to the tundish goes through significant temperature decline and may solidify in severe cases.